This multi-colored, hand-colored map of eastern Siberia shows the state of geographic knowledge at the beginning of the last quarter of the 18th century. The geographic grid and the mapping of the rivers are well-executed. Sakhalin Island is shown, but is poorly mapped. The work is by Johann Treskot (1721-86), a cartographer at the Geographical Department of the Academy of Sciences in Saint Petersburg, who compiled many of the maps published by the academy from the 1740s to the 1780s.